Information processing apparatus and method for supplying electrical power

ABSTRACT

An information processing apparatus includes: a plurality of electric power generating elements; detection means for determining whether each of the plurality of electric power generating elements has an electromotive force equal to or higher than a predetermined value; determination means determining an input operation performed by a user by identifying an electric power generating element having an electromotive force below the predetermined value when at least one of the plurality of electric power generating elements is determined as having an electromotive force below the predetermined value according to the detection means; processing means carrying out a process associate with the input operation determined by the determination means; and bypass means which is provided in parallel with the electric power generating elements and through which a current flows when the electric power generating elements have an electromotive force below the predetermined value.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/731,336, filed Dec. 31, 2012, which is a continuation of U.S.application Ser. No. 12/772,768, filed May 3, 2010, now U.S. Pat. No.8,370,655, issued Feb. 5, 2013, which claims the benefit of priority ofJapanese Patent Application No. JP 2009-114194, filed May 11, 2009, thesubject matter of each of which is incorporated herein by reference inits entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an information processing apparatus andan information processing method. More particularly, the inventionrelates to an information processing apparatus which can be suppliedwith required electric power even when part of a plurality ofseries-connected batteries thereof supplies no electricity and to aninformation processing method for such an apparatus.

2. Description of the Related Art

When an electronic apparatus is provided with user interfaces such asoperation buttons, the apparatus can be made easy to operate for a userby assigning a unique purpose to each operation button, e.g.,associating the buttons with commands in a one-to-one relationship.However, when a unique purpose is assigned to each operation button, thenumber of operation buttons increases. Such an approach thereforeresults in disadvantages in some aspects such as difficulty in makingthe electronic apparatus compact and increased complicatedness ofoperations encountered by a user.

In the related art, an optical sensor is sometimes used as a userinterface. For example, JP-A-2000-181602 (Patent Document 1) disclosesan invention according to which it is determined that an optical sensorhas been operated when light radiated from a light emitting portiontoward a light receiving portion is interrupted by a user.

SUMMARY OF THE INVENTION

When a compact electronic apparatus is provided with a solar battery, itmay be required to provide the solar battery on an outer lateral surfaceof a housing along with operation buttons. Then, it may not be possibleto accommodate a sufficient area for each of the elements. Further, whena plurality of solar batteries are connected in series to obtainrequired electric power, the required electric power cannot be obtainedin such a situation that one of the solar batteries generates noelectricity to disallow a current to flow through the entire group ofbatteries.

Under such circumstances, it is desirable to allow electric power to besupplied with stability by electric power generating elementsrepresented by solar batteries and to provide such electric powergenerating elements with functions of user interfaces. Thus, spacesaving can be achieved in an apparatus having such elements.

According to an embodiment of the invention, there is provided aninformation processing apparatus including a plurality of electric powergenerating elements, detection means for determining whether each of theplurality of electric power generating elements has an electromotiveforce equal to or higher than a predetermined value, determination meansdetermining an input operation performed by a user by identifying anelectric power generating element having an electromotive force belowthe predetermined value when at least one of the plurality of electricpower generating elements is determined as having an electromotive forcebelow the predetermined value according to the detection means,processing means carrying out a process associate with the inputoperation determined by the determination means, and bypass means whichis provided in parallel with the electric power generating elements andthrough which a current flows when the electric power generatingelements have an electromotive force below the predetermined value.

The plurality of electric power generating elements may be connected inseries. The apparatus may further include supplying means supplying thevalue of a total electromotive force of the plurality of electric powergenerating elements to the determination means. The determination meansmay determine the input operation when the value of the totalelectromotive force supplied by the supplying means is equal to orhigher than a predetermined value.

The detection means may detect an electromotive force of the electricpower generating element.

The detection means may be connected in series with the bypass means todetect a current flowing through the bypass means.

The electric power generating elements may be solar battery cells.

The information processing apparatus may be incorporated in a mobiletelephone.

The information processing apparatus may form part of an IC card.

According to another embodiment of the invention, there is provided aninformation processing method of an information processing apparatusincluding a plurality of electric power generating elements, detectionmeans, determination means, processing means, and bypass means providedin parallel with the electric power generating elements. The methodincludes the steps of determining by the detection means whether each ofthe plurality of electric power generating elements has an electromotiveforce equal to or higher than a predetermined value, identifying anelectric power generating element having an electromotive force belowthe predetermined value and determining an input operation performed bya user by the determination means when at least one of the plurality ofelectric power generating elements is determined as having anelectromotive force below the predetermined value according to thedetection means, carrying out a process associate with the inputoperation by the processing means, and causing a current to flow throughthe bypass means when the electric power generating elements have anelectromotive force below the predetermined value.

In the information processing apparatus and method according to theembodiments of the invention, it is determined whether each of aplurality of electric power generating elements has an electromotiveforce equal to or higher than a predetermined value. An input operationperformed by a user is determined by identifying an electric powergenerating element having an electromotive force below the predeterminedvalue when it is determined that at least one of the electric powergenerating element has an electromotive force below the predeterminedvalue. A process is carried out based on the determination. Theapparatus is configured such that a current flows through a bypassprovided in parallel with an electric power generating element when theelectric power generating element has an electromotive force below thepredetermined value.

According to the embodiments of the invention, electric power can besupplied with stability by electric power generating elements which aretypically solar batteries, and such electric power generating elementscan be provided with functions of user interfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a configuration of an embodiment of a mobileinformation processing apparatus according to the invention;

FIG. 2 is a diagram showing an exemplary configuration of the mobileinformation processing apparatus;

FIG. 3 is a diagram showing an exemplary circuit configuration of themobile information processing apparatus;

FIG. 4 is a diagram for explaining the flow of currents in the mobileinformation processing apparatus;

FIG. 5 is a diagram showing an exemplary circuit configuration of themobile information processing apparatus;

FIG. 6 is a flow chart for explaining processes associated withdetermination of an operation;

FIG. 7 is a diagram showing another exemplary circuit configuration ofthe mobile information processing apparatus;

FIG. 8 is a diagram for explaining the flow of currents in the mobileinformation processing apparatus;

FIG. 9 is a diagram showing another exemplary circuit configuration ofthe mobile information processing apparatus; and

FIG. 10 is a flow chart for explaining processes associated withdetermination of an operation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the invention will now be described with reference to thedrawings.

[Configuration of Mobile Information Processing Apparatus]

FIG. 1 is a schematic illustration of a mobile information processingapparatus 10 that is an embodiment of the invention. For example, themobile information processing apparatus 10 is an IC (integrated circuit)card having the same size as that of credit cards, and the apparatusincludes a plurality of solar cells (four solar cells in the embodimentshown in FIG. 1) 11-1 to 11-4 and a display 12 for displayingpredetermined information provided on an outer lateral surface thereof.The mobile information processing apparatus 10 having such aconfiguration may be used as a device which forms part of a mobilephone.

At least one command is associated with each of the solar cells 11-1 to11-4. The commands are identified by states of power generation at thesolar cells 11-1 to 11-4. When a user wishes to input any of thecommand, the command can be input by performing an operation such ascovering some of the solar cells 11-1 to 11-4. As a result, the solarcells 11-1 to 11-4 can be used as user interfaces, and there is no needfor disposing buttons or the like on an outer surface of the mobileinformation processing apparatus 10.

The number of commands assigned to each of the solar battery cells 11-1to 11-4 may be arbitrarily set. For example, one command may be assignedto each solar battery cell 11. Alternatively, a plurality of commandsmay alternatively be assigned to each cell, and determination as towhich of the cells is selected may be made according to the number ofuser inputs. Further, the meaning of one command may be represented by acombination of plural solar battery cells 11. Thus, the small number ofsolar battery cells 11 can be combined to define various commands, andthe number of the commands thus defined may exceed the number of cells.

A description will now be made on a configuration of the mobileinformation processing apparatus 10 of the present embodiment andoperations of the apparatus to achieve the functions as thus described.

The solar battery cells 11-1 to 11-4 not only convert light irradiatingthem into electric power but also function as user interfaces.Specifically, when any of the solar battery cells 11-1 to 11-4 iscovered by a finger of a user, the action is detected as a selectingoperation performed by the user, and a process associated with theoperation is performed. Hereinafter, the solar battery cells 11-1 to11-4 may be simply referred as “solar battery cells 11” when there is noneed for distinguishing the cells from each other. Reference numeralsassigned to other parts of the apparatus may be similarly given in suchabbreviated forms.

The solar battery cells 11 converting irradiating light into electricpower may be replaced by electric power generating elements whichconvert heat generated from light irradiating them into electric power.The invention is not limited to the use of four solar battery cells 11.For example, electronic paper or a liquid crystal panel may be used asthe display 12.

FIG. 2 shows an exemplary configuration of the mobile informationprocessing apparatus 10. In addition to the solar battery cells 11 andthe display 12 provided on the outer lateral surface as described above,the mobile information processing apparatus 10 may include a poweraccumulating section 21 which supplies electric power obtained from thesolar battery cells 11 to parts of the apparatus provided downstream ofthe section in a stable manner and a control section 23 which executesprocesses according to operations performed by a user on the solarbattery cells 11 serving as user interfaces.

A cell voltage monitoring circuit 22-1 detects the voltage of electricpower generated by the solar battery cell 11-1 and notifies an operationdetermining section 24 in the control section 23 of the voltage. Thesolar battery cell 11-1 outputs the electric power generated by itselfto the power accumulating section 21. The solar battery cells 11-2 to11-4 are similar to the solar battery cell 11-1 in configuration. Thesolar battery cells 11-1 to 11-4 are connected in series. The cells areconfigured such that desired electric power can be obtained when theyare connected in series.

The power accumulating section 21 is constituted by a storage battery orcapacitor. The section accumulates electric power from the solar batterycells 11-1 to 11-4 to obtain a desired voltage and supplies the electricpower to the display 12 and the control section 23 provided downstreamof the section.

The control section 23 executes programs held in a memory 25incorporated in itself to implement an operation determining section 24,a signal processing section 26, and a display control section 27 on asoftware basis. The operation determining section 24 determines whetherany of the solar battery cells 11-1 to 11-4 has been operated by a user(for example, covered by a finger) based on results of detectionperformed by cell voltage monitoring circuits 22-1 to 22-4, and thesection notifies the signal processing section 26 of the result of thedetermination. The signal processing section 26 performs a processaccording to the determination results thus informed and outputs theresult of the process to the display control section 27.

For example, when the mobile information processing apparatus 10 isprovided with such a function, various services can be implemented usingthe mobile information processing apparatus 10, including electric moneysettlement services and services for providing various types ofinformation such as weather forecasts. When the content of servicesprovided to a user changes depending on applications to be executed, itbecomes necessary to change commands in accordance with services to beprovided. In such a case, commands assigned to the solar battery cells11 may be changed depending on applications to be executed.

Assigning no command to some of the solar battery cells is an approachwhich can be taken in such a case, and it is also possible to assign onecommand to a combination of plural solar battery cells 11. Further,different processes may be performed depending on modes of inputs from auser. For example, the apparatus may be set up such that differentcommands will be input depending on the number of times the same solarbattery cell 11 is covered or the order in which the solar battery cells11 are covered.

The mobile information processing apparatus 10 may be incorporated in akeyboard of a personal computer or a mobile phone to serve as part ofsuch apparatus.

[Circuit Configuration]

FIG. 3 is a diagram showing an exemplary circuit configuration of themobile information processing apparatus 10. The solar battery cells 11-1to 11-4 are connected in series. A negative side of the solar batterycell 11-4 is grounded. A positive side of the solar battery cell 11-4 isconnected to a negative side of the solar battery cell 11-3. A positiveside of the solar battery cell 11-3 is connected to a negative side ofthe solar battery cell 11-2. A positive side of the solar battery cell11-2 is connected to a negative side of the solar battery cell 11-1. Apositive side of the solar battery cell 11-1 is connected to one end ofthe cell voltage monitoring circuit 22-1 on an input side of thecircuit.

Another end of the cell voltage monitoring circuit 22-1 on the inputside thereof is connected to a negative side of the solar battery cell11-1 (the positive side of the solar battery cell 11-2). The positiveside of the solar battery cell 11-2 is connected to one end of the cellvoltage monitoring circuit 22-2 on an input side of the circuit. Anotherend of the cell voltage monitoring circuit 22-2 on the input sidethereof is connected to the negative side of the solar battery cell 11-2(the positive side of the solar battery cell 11-3).

The positive side of the solar battery cell 11-3 is connected to one endof the cell voltage monitoring circuit 22-3 on an input side of thecircuit. Another end of the cell voltage monitoring circuit 22-3 on theinput side thereof is connected to the negative side of the solarbattery cell 11-3 (the positive side of the solar battery cell 11-4).The positive side of the solar battery cell 11-4 is connected to one endof the cell voltage monitoring circuit 22-4 on an input side of thecircuit. Another end of the cell voltage monitoring circuit 22-4 on theinput side thereof is connected to the negative side of the solarbattery cell 11-4 (ground).

The cell voltage monitoring circuits 22-1 to 22-4 measure voltages(potentials) of the solar battery cells 11-1 to 11-4, respectively. Thecell voltage monitoring circuit 22-1 measures the voltage of the solarbattery cell 11-1 and outputs the result of the measurement to theoperation determining section 24. The cell voltage monitoring circuit22-2 measures the voltage of the solar battery cell 11-2 and outputs theresult of the measurement to the operation determining section 24. Thecell voltage monitoring circuit 22-3 measures the voltage of the solarbattery cell 11-3 and outputs the result of the measurement to theoperation determining section 24. The cell voltage monitoring circuit22-4 measures the voltage of the solar battery cell 11-4 and outputs theresult of the measurement to the operation determining section 24.

Specifically, the cell voltage monitoring circuits 22 calculate adifference between two voltages input thereto and output the result ofthe calculation to the operation determining section 24. When a voltageis measured as a difference as thus described, the cell voltagemonitoring circuits 22 may be differential circuits. For example, whenthe solar battery cells 11 generate electric power of 1 volt, the cellvoltage monitoring circuits 22 output either of numerical values “0” and“1” to the operation determining section 24. For example, when the solarbattery cell 11-1 generates an electromotive force, the cell voltagemonitoring circuit 22-1 outputs “1” to the operation determining section24. When the cell generates no electromotive force, the cell voltagemonitoring circuit 22-1 outputs “0” to the operation determining section24.

The cell voltage monitoring circuit 22-1 is not required to measure theelectromotive force of the solar battery cell 11-1 exactly, and thecircuit may be configured to output “1” when there is an electromotiveforce equal to or higher than a predetermined value and to output “0”when there is an electromotive force below the predetermined value.Obviously, the circuit may alternatively be configured to output “0”when there is an electromotive force equal to or higher than apredetermined value and to output “1” when there is an electromotiveforce below the predetermined value. The following description is basedon an assumption that the apparatus has the configuration to output “1”when there is an electromotive force equal to or higher than apredetermined value and to output and “0” when there is an electromotiveforce below the predetermined value.

The solar battery cell 11-1 generates no electromotive force when a useruses the solar battery cell 11-1 as a switch, e.g., when the solarbattery cell 11-1 is covered by a finger. Therefore, when the valueinput from the cell voltage monitoring circuit 22-1 is “0”, theoperation determining section 24 determines that the solar battery cell11-1 has been operated as a switch by the user. The other solar batterycells 11-2 to 11-4 and the other cell voltage monitoring circuits 22-2to 22-4 are similar in configuration to the solar battery cell 11-1 andthe cell voltage monitoring circuit 22-1, respectively.

When a solar battery cell 11 is covered by a finger or the like and isthereby disabled from generating an electromotive force, the internalresistance of the solar battery cell increases, and the cell mayconsequently operate as a pseudo-resistor. For example, when the solarbattery cell 11-1 is covered by a finger or the like and is therebydisabled from generating an electromotive force, the internal resistanceof the solar battery cell 11-1 increases. Thus, the cell functions as aresistor rather than a power supply, which is undesirable. In such astate, no current flows through the solar battery cell 11-1. As aresult, no current flows into the power accumulating section 21, anddesired electronic power cannot be obtained.

The description will be continued with reference to FIG. 4. When thesolar battery cell 11-1 is not covered by a finger and is thereforegenerating an electromotive force, a current i1 flows into the poweraccumulating section 21 after flowing through the solar battery cell11-4, the solar battery cell 11-3, the solar battery cell 11-2, and thesolar battery cell 11-1, as shown in FIG. 4. When the solar battery cell11-1 is covered by a finger, the solar battery cell 11-1 functions as apseudo-resistor as shown in FIG. 4. When the solar battery cell 11-1functions as a resistor, the current i1 does not flow through the solarbattery cell 11-1. Consequently, no current flows into the poweraccumulating section 21, and no electric power is accumulated in thepower accumulating section 21. In such a state, no electric power issupplied to the mobile information processing apparatus 10, and theapparatus is therefore disabled.

According to the embodiment of the invention, in order to prevent theoccurrence of the state in which no current flows into the poweraccumulating section 21, a bypass diode 51-1 is provided to allow acurrent i2 to flow, as shown in FIG. 4. Specifically, when the solarbattery cell 11-1 functions as a pseudo-resistor, the current i2 flowsthrough the solar battery cell 11-4, the solar battery cell 11-3, thesolar battery cell 11-2, and the bypass diode 51-1. As a result,electric power is supplied to the power accumulating section 21.

Referring again to the circuit configuration shown in FIG. 3, the bypassdiode 51-1 is provided in parallel with the solar battery cell 11-1.Similarly, a bypass diode 51-2 is provided in parallel with the solarbattery cell 11-2. A bypass diode 51-3 is provided in parallel with thesolar battery cell 11-3. A bypass diode 51-4 is provided in parallelwith the solar battery cell 11-4.

In such a configuration, a current flows through the bypass diode 51-1when the solar battery cell 11-1 functions as a switch. A current flowsthrough the bypass diode 51-2 when the solar battery cell 11-2 functionsas a switch. A current flows through the bypass diode 51-3 when thesolar battery cell 11-3 functions as a switch. A current flows throughthe bypass diode 51-4 when the solar battery cell 11-4 functions as aswitch. Thus, the circuit configuration shown in FIG. 3 allows a currentto flow into the power accumulating section 21 to accumulate electricpower therein even when any of the solar battery cells 11-1 to 11-4functions as a switch and therefore acts as a pseudo-resistor.

[Configuration with Total Voltage Monitoring Circuit]

When all of the solar battery cells 11-1 to 11-4 are covered by a hand,none of the solar battery cells 11-1 to 11-4 generate electric power,and each of the cell voltage monitoring circuits 22-1 to 22-4 outputsthe value “0”. In such a state, no electric power is accumulated in thepower accumulating section 21, and the mobile information processingapparatus 10 is disabled. However, in a case wherein the mobileinformation processing apparatus 10 is provided with, for example, abackup electric power section for supplying electric power in such asituation (such a case will be referred to as “first case”), the mobileinformation processing apparatus 10 operates even in the state in whichnone of the solar battery cells 11 generate electricity.

Even if no backup electric power section is provided, the mobileinformation processing apparatus 10 is kept operating for some time byelectric power accumulated in the power accumulating section 21 evenwhen each of the cell voltage monitoring circuits 22-1 to 22-4 outputsthe value “0” (such a case will be referred to as “second case”).

In the first or second case wherein the mobile information processingapparatus 10 operates even though each of the cell voltage monitoringcircuits 22-1 to 22-4 outputs the value “0”, the operation determiningsection 24 determines that all of the solar battery cells 11-1 to 11-4have been operated as switches.

In such a situation, the operation determining section 24 determinesthat all of the solar battery cells 11-1 to 11-4 have been operated andallows a process associated with the determination to be performed inthe first case. Let us assume that a sufficient quantity of light cannotbe obtained because, for example, the mobile information processingapparatus 10 has been left in a dark place and that each of the cellvoltage monitoring circuits 22-1 to 22-4 consequently outputs the value“0”. In such a situation, the operation determining section 24 maydetermine that all of the solar battery cells 11-1 to 11-4 have beenoperated, and the process associated with the determination may beexecuted. That is, the process can be executed in a situation where itshould not be executed.

In the second case, when the operation determining section 24 determinesthat all of the solar battery cells 11-1 to 11-4 have been operated toallow the process associated with the determination to be executed, theamount of electric power accumulated in the power accumulating section21 may have become too low to execute the process (to allow the mobileinformation processing apparatus 10 to operate). That is, the processmay not be executed even though the execution of the process isinstructed by the user.

In order to prevent such a situation, the mobile information processingapparatus 10 is provided with a circuit for monitoring the total voltageof the solar battery cells 11-1 to 11-4. FIG. 5 is a diagram showing aconfiguration of the mobile information processing apparatus 10 in whichthe circuit for monitoring the total voltage of the solar battery cells11-1 to 11-4 is provided. The mobile information processing apparatus 10shown in FIG. 5 is configured by adding a total voltage monitoringcircuit 71 to a mobile information processing apparatus 10 as shown inFIG. 3.

The total voltage monitoring circuit 71 is connected to the positiveside of the solar battery cell 11-1 and one end of the bypass diode51-1. The total voltage monitoring circuit 71 is a circuit formonitoring the voltage supplied to the power accumulating section 21 orthe total voltage of the solar battery cells 11-1 to 11-4. The result ofthe monitoring is supplied from the total voltage monitoring circuit 71to the operation determining section 24. In a case wherein the result ofmonitoring supplied from the total voltage monitoring circuit 71 islower than a predetermined voltage, even when it is determined that thesolar battery cells 11-1 to 11-4 have been operated as switches, theprocess associated with the determination is not executed. In otherwords, the operation determining section 24 determines whether the solarbattery cells 11-1 to 11-4 have been operated as switches and allows theprocess associated with the determination to be executed, when theresult of monitoring supplied from the total voltage monitoring circuit71 is equal to or higher than the predetermined voltage.

[Processes at Operation Determining Section]

Processes performed by the operation determining section 24 of themobile information processing apparatus 10 shown in FIG. 5 will now bedescribed with reference to the flow chart of FIG. 6.

At step S11, the operation determining section 24 detects the voltagesof the solar battery cells 11-1 to 11-4. The operation determiningsection 24 detects the voltages of the solar battery cells 11-1 to 11-4from the values supplied by the respective cell voltage monitoringcircuits 22-1 to 22-4. At step S12, it is determined whether there isany solar battery cell 11 whose voltage has dropped. The operationdetermining section 24 performs the process at step S12 by monitoringthe values supplied from the cell voltage monitoring circuits 22-1 to22-4 and determining whether any of the cell voltage monitoring circuits22 has supplied the value “0”.

When it is determined at step S12 that there is no solar battery cell 11whose voltage has dropped, the process flow returns to step S11 torepeat the processes at steps S11 and S12. Specifically, it isdetermined that the solar battery cells 11 have not been operated asswitches, and the processes at steps S11 and S12 are repeated until itis determined that any of the cells has been operated as a switch.

When it is determined at step S12 that there is a solar battery cell 11whose voltage has dropped or when it is determined that there is a solarbattery cell 11 which has been operated as a switch, the process flowproceeds to step S13. At step S13, it is determined whether the totalvoltage of the cells is lower than the predetermined value. Thedetermination is carried out by the operation determining section 24using the result of monitoring performed by the total voltage monitoringcircuit 71. When it is determined at step S13 that the total voltage isnot lower than the predetermined value, the process flow proceeds tostep S14.

At step S14, it is determined that the solar battery cell 11 on which avoltage drop has been detected is a cell which has been operated. Theoperation determining section 24 identifies the solar battery cell 11which has been operated by identifying the cell voltage monitoringcircuit 22 outputting the value “0” (the value smaller than thepredetermined value) among the cell voltage monitoring circuits 22-1 to22-4.

At step S15, a process associated with the operation is executed.Specifically, the operation determining section 24 notifies the signalprocessing section 26 of the process associated with the solar batterycell 11 identified as having been operated. For example, the operationdetermining section 24 holds a table listing the solar battery cells11-1 to 11-4 along with processes which are associated with the cellsrespectively. The section 24 refers to the table to read out the processassociated with the solar battery cell 11 identified as having beenoperated and notifies the signal processing section 26 of the processthus read out. The signal processing section 26 executes the processbased on the notice.

When the signal processing section 26 executes the process, for example,the display control section 27 controls the display 12 based on theresult of the process input to the same. For example, when the solarbattery cell 11-1 has been operated, the signal processing section 26outputs image data A to the display control section 27, and the displaycontrol section 27 causes the display 12 to display an image associatedwith the image data A. For example, when the solar battery cell 11-2 hasbeen operated, the signal processing section 26 outputs image data B tothe display control section 27, and the display control section 27causes the display 12 to display an image associated with the image dataB.

When it is determined at step S13 that the total voltage is lower thanthe predetermined value, the process flow proceeds to step S16. At stepS16, the cells are disabled from functioning as switches. Let us assumethat the value monitored by a cell voltage monitoring circuit 22 issmaller than the predetermined value (specifically, the monitored valueis “0”) when the value monitored by the total voltage monitoring circuit71 is smaller than the predetermined value. In such a case, theoperation determining section 24 is restrained from determining that anoperation has been performed on the solar battery cell 11 associatedwith the cell voltage monitoring circuit 22 outputting a value smallerthan the predetermined value. Such control is exercised for the reasonsdescribed above.

The processes described above allow the solar battery cells 11 to beused not only as electric power sections generating and supplyingelectric power but also as user interfaces for accepting instructionsfrom a user. Even when a solar battery cell 11 is used as a userinterface and the cell therefore generates no electromotive force andfunctions as a pseudo-resistor, the above-described configurationprevents interruption of a current flow in the circuit. Thus, theaccumulation of electric power in the power accumulation section 21 canbe kept enabled.

Further, the use of the configuration for monitoring the total voltageof the cells makes it possible to prevent erroneous operations. Becauseof such a capability, the configuration allows more significant spacesavings to be achieved compared to configurations in which solarbatteries are provided separately from user interfaces such as operationswitches.

When the mobile information processing apparatus 10 has theconfiguration shown in FIG. 3, the processes at steps S13 and S16 areomitted. In the configuration shown in FIG. 3, for example, when resultsof monitoring performed by the cell voltage monitoring circuits 22-1 to22-4 are lower than the predetermined value, the operation determiningsection 24 makes no determination (when all of the solar battery cells11 have been operated, the monitoring result is treated as a commandinhibiting any action), whereby the occurrence of an erroneous operationcan be prevented.

[Another Configuration of Mobile Information Processing Apparatus]

FIG. 7 is a diagram showing another configuration of a mobileinformation processing apparatus. In the mobile information processingapparatus 10 described above and shown in, for example, in FIG. 3,voltages of electric power generated by the solar battery cells 11 aremonitored by the cell voltage monitoring circuit 22 to identify anysolar battery cell 11 which has been operated. Further, the apparatushas a configuration in which a current flows through a bypass diode 51associated with a solar battery cell 11 when the cell is operated. It istherefore possible to provide a mobile information processing apparatushaving such a configuration that a solar battery cell 11 is identifiedas having been operated when a current flows through a bypass diode 51associated with the solar battery cell 11.

A mobile information processing apparatus 100 shown in FIG. 7 includescurrent detecting sections 101. The mobile information processingapparatus 100 shown in FIG. 7 also includes determination circuits 102-1to 102-4 determining whether solar battery cells 11 have been operatedor not by monitoring detection performed by the current detectingsections 101. Other parts of the apparatus are indicated by referencenumerals identical to those used in the mobile information processingapparatus 10 shown in FIG. 3 and will not be described below becausethey are similar to the corresponding parts of the apparatus 10.

One end of a current detecting section 101-1 is connected to a negativeside of a solar battery cell 11-1, and another end of the section isconnected to one end of a bypass diode 51-1. One end of a currentdetecting section 101-2 is connected to a negative side of a solarbattery cell 11-2, and another end of the section is connected to oneend of a bypass diode 51-2. One end of a current detecting section 101-3is connected to a negative side of a solar battery cell 11-3, andanother end of the section is connected to one end of a bypass diode51-3. One end of a current detecting section 101-4 is connected to anegative side of a solar battery cell 11-4, and another end of thesection is connected to one end of a bypass diode 51-4.

The determination circuit 102-1 is connected to each of input and outputsides of the current detecting section 101-1. The input side of thecurrent detecting section 101-1 is on the negative side of the solarbattery cell 11-1, and the output side of the section is connected tothe bypass diode 51-1. Similarly, the determination circuit 102-2 isconnected to each of input and output sides of the current detectingsection 101-2. The determination circuit 102-3 is connected to each ofinput and output sides of the current detecting section 101-3. Thedetermination circuit 102-4 is connected to each of input and outputsides of the current detecting section 101-4.

The flow of currents in the mobile information processing apparatusshown in FIG. 7 will now be described with reference to FIG. 8. When thesolar battery cell 11-1 is not covered by a finger and is thereforegenerating an electromotive force, a current i1 flows into a poweraccumulating section 21 after flowing through the solar battery cell11-4, the solar battery cell 11-3, the solar battery cell 11-2, and thesolar battery cell 11-1, as shown in FIG. 8. When the solar battery cell11-1 is covered by a finger, the solar battery cell 11-1 functions as apseudo-resistor as shown in FIG. 8. When the solar battery cell 11-1functions as a resistor, the current it does not flow through the solarbattery cell 11-1. Consequently, no current flows into the poweraccumulating section 21, and no electric power is accumulated in thepower accumulating section 21. In such a state, no electric power issupplied to the mobile information processing apparatus 100, and theapparatus is therefore disabled.

According to the embodiment of the invention, in order to prevent theoccurrence of the state in which no current flows into the poweraccumulating section 21, the bypass diode 51-1 is provided to allow acurrent i2 to flow, as shown in FIG. 8. Specifically, when the solarbattery cell 11-1 functions as a pseudo-resistor, the current i2 flowsthrough the solar battery cell 11-4, the solar battery cell 11-3, thesolar battery cell 11-2, and the bypass diode 51-1. As a result, thesupply of electric power to the power accumulating section 21 can bemaintained.

The current i2 flows through the current detecting section 101-1.Therefore, when the solar battery cell 11-1 has been operated, thecurrent detecting section 101-1 detects the current i2. Thedetermination circuit 102-1 can determine whether the solar battery cell11-1 has been operated by monitoring the detection or determiningwhether the current has flowed through the current detecting section101-1. Since determination is carried out in such a manner, the currentdetecting sections 101 may be formed by resistors (which preferably havea low resistance), and the determination circuits 102 may be configuredto determine whether the current has flowed through the respectivecurrent detecting sections 101 by measuring potential differencesbetween the resistors.

The determination circuits 102-2 to 102-4 determine that the respectivesolar battery cells 11-2 to 11-4 have been operated when the respectivecurrent detecting sections 101-2 to 101-4 detect the current, in thesame manner as the determination circuit 102-1. The determinationcircuits 101-1 to 101-4 output the results of determination to anoperation determining section 103. The operation determining section 103identifies a solar battery cell 11 which has been operated based on theresults of determination output from the determination circuits 101-1 to101-4.

The mobile information processing apparatus 100 may be configured suchthat the cells are disabled from functioning as switches when the totalvoltage of the cells has dropped. FIG. 9 shows an exemplaryconfiguration of a mobile information processing apparatus 100configured such that the cells are disabled from functioning as switcheswhen the total voltage of the cells has dropped.

FIG. 9 is a diagram showing a configuration of the mobile informationprocessing apparatus 100 in which a circuit for monitoring the totalvoltage (the total electromotive force) of the solar battery cells 11-1to 11-4 is provided. The mobile information processing apparatus 100shown in FIG. 9 is configured by adding a total voltage monitoringcircuit 111 to a mobile information processing apparatus 100 as shown inFIG. 7.

The total voltage monitoring circuit 111 is connected to the positiveside of the solar battery cell 11-1 and one end of the bypass diode51-1. The total voltage monitoring circuit 111 is a circuit formonitoring the voltage supplied to the power accumulating section 21 orthe total voltage of the solar battery cells 11-1 to 11-4. The result ofthe monitoring is supplied from the total voltage monitoring circuit 111to the operation determining section 103. In a case wherein the resultof monitoring supplied from the total voltage monitoring circuit 111 islower than a predetermined voltage, even when it is determined that thesolar battery cells 11-1 to 11-4 have been operated as switches, aprocess associated with the determination is not executed.

[Processes at Operation Determining Section]

Processes in the mobile information processing apparatus 100 shown inFIG. 9, in particular, processes performed by the operation determiningsection 103 will now be described with reference to the flow chart ofFIG. 10.

At step S31, current detecting sections 101 detect currents flowingthrough themselves. When a current is detected by a current detectingsection 101, a determination circuit 102 associated with the sectiondetermines that a current has flowed. The result of the determination isoutput to the operation determining section 103.

At step S32, the operation determining section 103 determines whetherthere is a determination circuit 102 which has determined the presenceof a current flow. When it is determined at step S32 that there is nodetermination circuit 102 which has determined the presence of a currentflow, the process flow returns to step S31 to repeat steps S31 and S32.That is, it is determined that the solar battery cells 11 have not beenoperated as switches, and the processes at steps S31 and S32 arerepeated until it is determined that any of the cells has been operatedas a switch.

When it is determined at step S32 that there is a determination circuit102 which has determined the presence of a current flow or when it isdetermined that there is a solar battery cell 11 which has been operatedas a switch, the process flow proceeds to step S33. At step S33, it isdetermined whether the total voltage of the cells is lower than apredetermined value. The determination is carried out by the operationdetermining section 103 using results of monitoring performed by thetotal voltage monitoring circuit 111. When it is determined at step S33that the total voltage is not lower than the predetermined value, theprocess flow proceeds to step S34.

At step S34, the determination circuit 102 which has determined thepresence of a current flow is identified, and the solar battery cell 11associated with the determination circuit 102 is identified to be a cellwhich has been operated. At step S35, a process associated with theoperation is executed. Specifically, the operation determining section103 notifies the signal processing section 26 of a process associatedwith the solar battery cell 11 which has been identified as having beenoperated, and the signal processing section 26 executes the process.

When it is determined at step S33 that the total voltage is lower thanthe predetermined voltage, the process flow proceeds to step S36. Atstep S36, the cells are disabled from functioning as switches. Let usassume that the value monitored by a cell voltage monitoring circuit 22is smaller than a predetermined value when the value monitored by thetotal voltage monitoring circuit 111 is smaller than the predeterminedvalue. In such a case, the operation determining section 103 isrestrained from determining that an operation has been performed on thesolar battery cell 11 associated with the cell voltage monitoringcircuit 22 outputting a value smaller than the predetermined value.

The processes described above allow the solar battery cells 11 to beused not only as electric power sections generating and supplyingelectric power but also as user interfaces for accepting instructionsfrom a user. Even when a solar battery cell 11 is used as a userinterface and the cell therefore generates no electromotive force andfunctions as a pseudo-resistor, the interruption of a current flow canbe prevented in the circuit. Thus, the accumulation of electric power inthe power accumulation section 21 can be kept enabled.

Further, the use of the configuration for monitoring the total voltageof the cells makes it possible to prevent erroneous operations. Becauseof such a capability, the configuration allows more significant spacesavings to be achieved compared to configurations in which solarbatteries are provided separately from user interfaces such as operationswitches.

The invention can be applied not only to mobile information processingapparatus like the present embodiment but also to any electronicapparatus having electric power generating elements represented by solarbatteries.

The above-described series of processes may be executed on eitherhardware or software. When the series of processes is executed on asoftware basis, programs forming the software are installed in acomputer. The invention may be implemented using computers includingcomputers incorporated in dedicated hardware and general-purposepersonal computers in which various programs can be installed to executevarious functions.

Programs executed by such a computer may be programs for executing theprocesses described in this specification in a time sequential manner inthe order in which the processes are described. Alternatively, it ispossible to use programs executed in parallel or programs executed atappropriate timing as required such as when invoked.

In the present specification, the term “system” means the entirety of acomplex apparatus formed by a plurality of apparatus.

The present application contains subject matter related to thatdisclosed in Japanese Priority Patent Application JP 2009-114194 filedin the Japan Patent Office on May 11, 2009, the entire contents of whichis hereby incorporated by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. An apparatus comprising: a user interface including a plurality of electric power generating elements; a monitoring unit configured to monitor whether each electric power generating element in the plurality of electric power generating elements has an electromotive force of at least a first predetermined value; an identification unit configured to identify a first electric power generating element in the plurality of electric power generating elements having an electromotive force below the first predetermined value according to the monitoring unit; and a plurality of bypass units, including a first bypass unit in parallel with the first electric power generating element, wherein a current flows through the first bypass unit when the first electric power generating element identified by the identification unit has an electromotive force below the first predetermined value.
 2. The apparatus according to claim 1, wherein the plurality of electric power generating elements are connected in series.
 3. The apparatus according to claim 1, wherein the identification unit is further configured to identify a second electric power generating element in the plurality of electric power generating elements having an electromotive force below the first predetermined value according to the monitoring unit; and wherein the current flows through a second bypass unit in the plurality of bypass units in parallel with the second electric power generating element when the second electric power generating element identified by the identification unit has an electromotive force below the first predetermined value.
 4. The apparatus according to claim 3, further comprising: a controller configured to execute a process associated with the first electric power generating element and the second electric power generating element when the identification unit identifies each of the first electric power generating element and the second electric power generating element as having an electromotive force below the first predetermined value.
 5. The apparatus according to claim 4, wherein the controller is further configured to change the process associated with the first electric power generating element and the second electric power generating element based on the order in which the identification unit identifies the first electric power generating element as having an electromotive force below the first predetermined value and the second electric power generating element as an electromotive force below the first predetermined value.
 6. The apparatus according to claim 3, further comprising: a controller configured to execute a first process associated with the first electric power generating element when the identification unit identifies the first electric power generating element as having an electromotive force below the first predetermined value, and to execute a second process associated with the second electric power generating element when the identification unit identifies the second electric power generating element as having an electromotive force below the first predetermined value.
 7. The apparatus according to claim 1, further comprising: a controller configured to execute a process associated with the first electric power generating element when the identification unit identifies the first electric power generating element as having an electromotive force below the first predetermined value.
 8. The apparatus according to claim 7, wherein the controller is further configured to change the process associated with the first electric power generating element based on different applications to be executed.
 9. The apparatus according to claim 7, wherein the controller is further configured to change the process associated with the first electric power generating element based on the number of times the first electric power generating element is determined to have an electromotive force below the first predetermined value.
 10. The apparatus according to claim 7, further comprising: a total output monitoring unit configured to monitor a total electromotive force output from the plurality of electric power generating elements.
 11. The apparatus according to claim 10, wherein the controller is further configured not to execute the process associated with the first electric power generating element when a result of the monitoring by the total output monitoring unit is lower than a second predetermined value.
 12. The apparatus according to claim 7, wherein the controller is further configured to determine the process associated with the first electric power generating element based on a table.
 13. The apparatus according to claim 1, further comprising a power accumulation unit configured to accumulate electric power generated by the plurality of electric power generating elements and to supply electric power to the apparatus.
 14. The apparatus according to claim 1, further comprising a power accumulation unit configured to accumulate electric power from the current flowing through the first bypass unit when the first electric power generating element has an electromotive force below the first predetermined value and also flowing through at least a second electric power generating element in the plurality of electric power generating elements having an electromotive force of at least the first predetermined value.
 15. The apparatus according to claim 1, wherein the first electric power generating element operates as a switch when the first electric power generating element has an electromotive force below the first predetermined value.
 16. The apparatus according to claim 1, wherein the electric power generating elements are solar cells.
 17. The apparatus according to claim 1, wherein the apparatus is a mobile phone. 